Portable electronic devices are used for a variety of useful functions, including (i) communications devices such as mobile telephones, citizen band radios, family radio spectrum radio, and wireless internet devices, (ii) portable computing devices such as notebook computers, personal digital assistants, and calculators, (iii) military electronic devices, such as night visions devices, communications devices, precision GPS, laser targeting devices, data displays, and computing devices, and (iv) other items such as digital cameras, camcorders, global position satellite devices, portable electronic games, flashlights, radios, and audio CD/MP3 players. Further, many more such types of devices are being created all the time. In some cases, the new electronic devices have become critically important to public safety such as 911 emergency service on mobile telephones, or global position satellite devices for general aviation and marine use.
One common element in all these portable electronic devices is their need for portable electrical power. This has been traditionally solved by using assemblies of chemical batteries, either the one time use disposable batteries (such as alkaline, zinc-air), or the multiple use rechargeable batteries (such as nickel-cadmium, nickel-metal-hydride, lead-acid, lithium-ion).
Electronic devices can only be truly portable if their power sources are always available in the field. Disposable batteries have a finite capacity. One option is to carry a sufficient supply of spare disposable batteries. However, each of the electronic devices can have a different power requirement with different voltages and currents. As a result thereof, the user may be required to carry multiple different types of batteries. Further, on a long trip or mission, the user may have to carry multiple sets of backup batteries. Moreover, the used batteries create a significant waste problem because they often contain toxic chemicals such as lead or mercury. As a result thereof, in many in situations, it is not practical to carry sufficient spare batteries.
Rechargeable batteries must be near a power source to be recharged, typically, a source of 60 Hz/120V. This is generally not available in remote locations. Alternatively, dynamo style power generators have a long history of usage. However, these generators are bulky, lowpower, single voltage, single device, hard to crank, inefficient, no feedback, and/or dangerous to batteries.
In light of the above, there is the need for an efficient portable device to produce electrical energy in the field. Additionally, there is a need for a power source that can be used to generate output current and voltages to a wide range of different electronic devices with their various battery chemistries and power needs. Moreover, there is a need for a power source that is relatively easy and efficient to use and control. Further, there is a need for a power source that reduces user fatigue.